#include <iostream>
#include <memory>

int main()
{
    std::cout << "Hello, world!" << std::endl;

    int fd = 23;
    auto fd_deleter = [](int *pfd)
    {
        std::cout << "release " << *pfd << std::endl;
    };
    std::unique_ptr<int, decltype(fd_deleter)> fd_ptr(&fd, fd_deleter);

    return 0;
}
